This project will answer the following questions: a) Is the amygdala involved in generating the frontal electroencephalographic (EEG) asymmetry associated with negative affect? and b) Is the amygdala involved in the behavioral discrimination of conspecific facial expressions of threat and fear? The project will also assess the utility of in vivo gene transfer technology in the study of brain mechanisms of social cognition. The specific aims of the proposal are: 1) to test the hypothesis that the dorsolateral amygdala (LdA) and the basal amygdala (BA) are required for the frontal electrococephalographic (EEG) asymmetry in resting and stimulus-presentation conditions associated with negative affect; 2) to test the hypothesis that the LdA and the BA are required for normal behavioral discrimination of facial expressions of threat and fear; and 3) to show the applicability of gene transfer technology as a tool for the transient inactivation of the amygdala in the study of social cognition Local infusions of muscimol will be used to inactivate amygdaloid nuclei and effects of inactivation of EEG on behavior will be measured. Local inactivation via in vivo gene transfer into the amygdala will use adeno-associated virus carrying the gene for the allatostatin receptor (AlstR) from Drosophula melanogaster and infusion of allatostatin into the lateral ventricle.